Wave guide switch



March 11, 1952 c. w. MILLER 2,588,934

WAVE GUIDE SWITCH Filed Jan. 7, 1948 Inventor: Charles W. Mil ler",

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Patented Mar. 11, 1952 WAVE GUIDE SWITCH Charles W..Miller, Sale, England,- assignor to- General Electric Company, a corporation of New York Application January 7, 1948, Serial No. 965 In Great Britain August 21, 1946 6 Claims.

My invention relates to a Wave guide structure forguiding Wavesfor ultra high frequency and, more particularly, to a selective connection for a wave guide junction.

It is sometimes desirable to have a means of switching the path of guided waves such as where duplicate radar equipment is used and where a common antenna may be connected to either equipment.

It is an object of my invention to. providea two-way selective connection for a T wave guide junction.

A further object of my invention is to provide means for deflecting waves in one direction at a wave guide junction and for preventing their flow in the opposite direction.

Another objectof my invention is to provide switching means for controlling the paths of guided waves.

For additional objects and advantages, and for a better understanding of the invention, attention is now directed to the following description and accompanying drawing, and also to the appended claims in which the novel fea tures of the invention are particularly pointed In the drawing:

Fig. 1 Ba vertical cross-section of a T wave guide-junction in which my invention is embodied;

' Fig.- 2 is a vertical cross-section of a T wave guide junction showing another embodiment of my invention;

Fig. 3 is an end view of the structure as shown in Fig. 2; and

Fig. 4 is a, topview of the structure as shown in Fig. 2.

In Fig. l the main arm of the T wave guide junction is indicated by the symbol Y. The branches of the cross-arm are indicated by the symbols X1 and X2. According to my invention a selective connection is provided between the main arm Y'and the two branches X1 and X2 by means of a sliding block I. The positionof block i as shown in Fig. 1 is such as to provide communication between the wave guides Y and X2 with the wave guide X1 being cut off. When moved to the alternate position, as shown by the dotted lines in Fig. 1, communication is effected between the wave guides X1 and Y and the Wave guide X2 is. cut off. The block I is formed with pairs of conducting surfaces 2 and 4. In he embodiment shown, the member I is made symmetrical and hence the opposing surfaces 2 and 4 have both been accorded the same reference numerals. It will be observed that block l is of substantially inverted triangular form with an extension 3 of rectangular cross-section at the apex of the triangle. In the position illustrated, one wall 4 of the apex portiont' constitutes an extension of the adjacent wall of the main wave guide member Y, while the connecting oblique surface 2 serves to deflect waves passing between the wave guide Y and the wave guide X2, or vice versa, without causing reflection; The distance between the surface 2 and the inner corner of the wave guide X2 and Y; which in the drawing is indicated by the letter d, .is suitably chosen according to the frequency of the waves to be transmitted.

The block I is slidable between .the two positions, the alternate position beingindicated in dashed outline in'Fig. 1. The upper face is machined out as' shown at 5, leaving two contact portions 'iiwhich abut against the" upper walls'of the cross-member X1 and X2. By restricting the abutting portions to the surface provided by-the portions 6, satisfactory contact can be obtained. In order to seal the unused branch, the length of the lower side, that is, the width of the rectangular apex portion 3, is made equal to onequarter Wave length at the frequency of the signal to be transmitted.

In the modification as shown in Fig. 2, the sealing of the upper surface of the block I is effected by extension pieces I. Care must be taken that the ends of these extension pieces I do not causereflections. In order to actuate the block 1, an actuating block 8 is attached to it by screws 9 or any other suitable means. The screws 9 pass through aslot Iii in the upper wall of the waveguide X1 and X2. A spring I I is interposed between the actuating block 8 and the upper Wall of the wave guide so as to provide a degree of friction to retain it in position. The extension I also serves to cover the slot in so as to render the upper wall of the wave guide continuous for all positions of the block I. Movement of the block I is limited by adjustable stops l2 located at either end of the position of travel. Actuation may be efiected by any suitable toggle mechanism such as an actuating arm it.

While this arrangement is primarily designed for a T wave guide junction lying in the H plane, a similar arrangement may be used for a T wave guide junction lying in the E plane. The arrangement shown may be used in rectangular wave guides propagating H01 or TEm modes.

It will now be appreciated that block. I is slidacle along the cross-member of the T between operative positions in each of which it respectively blocks one of the cross-arms and provides connection between the alternative arm and the main member of the T. This block is formed with deflecting surfaces, one of which in each operative position lies across the outer corner of the passage between the innerconnected members so as to deflect waves around the corner without causing appreciable deflection.

While certain specific embodiments have been shown and described, it will, of course, be understood that various modifications may be made without departin from the invention. The appended claims are, therefore, intended to cover any such modifications within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a Wave guide structure, a main arm, a pair of branch cross arms, a metallic electromagnetic wave deflecting member slidable along said branch cross arms between alternate operative positions in each of which said deflecting member blocks electromagnetic wave transmission through one of said cross arms and provides electromagnetic Wave communication between the other arm and said main arm, said deflecting member being formed with deflecting surfaces, one of which in each'of said operative positions lies across the outer corner of the angle passage between said interconnected arms.

2. A T-shaped wave guide structure comprising, in combination, a main arm intersecting a pair of axially aligned transverse arms, selecing, in combination, a main arm intersecting a pair of axially aligned transverse arms, selective switching means for connecting said main arm with either one of said transverse arms for energy transfer therebetween while blocking energy transfer between said main arm and the other of said transverse arms, said means comprising an electrically reflecting block member movable within said tranverse arms to either, of two operating positions one on each side of said junction, said member being in conductive engagement with the wall of said transverse arms opposite said junction and having a free end in close-proximity to the opposite wall in either of said positions, said member having a thickness at its free end as measured axially along the unused -transverse arms substantially a A wave length at the predetermined operating frequency.

5. In a wave guide structure for operation at' high frequency, a pair of axially aligned arms, a second arm intersecting said axially aligned arms at a common junction point and lying substantially perpendicular to the longitudinal axis of passage for electromagnetic waves between one of said aligned arms and said second arm in either position and simultaneously blocking communication of electromagnetic waves between said second arm and the other of said aligned tive switching means for selectively connecting a having a free end in close proximity to the opposite wall in either of said positions.

'3. A T-shaped wave guide structure comprising, in combination, a main arm intersecting a pair of axially aligned transverse arms, selective switching means for connecting said main arm with only one of said transverse arm at a time for energy transfer therebetween, said means comprising .an electrically reflecting block member conductively supported within said transverse arms and selectively movable to either 4 of two positions on opposite sides of the junction with said main arm, said member being shaped to define in either position an extension of the adjacent wall of said main arm for a portion of the distance across said transverse arms and an angularly disposed flat reflectingsurface for the remaining portion of said distance.

4. In a T-shaped wave guide structure for operation at a predetermined frequency comprisarms.

6. A T-shaped wave guide structure comprising, in combination, a main arm intersecting a pair of axially aligned transverse arms, selective switching means for connecting said main arm with either one of said transverse arms for energy transfer therebetween while blocking transfer of energy between said main arm and the other of. said transverse arms; said means comprising a movable member conductively supported within said transverse arms and having a pair of reflecting surface spaced along the axis of said transverse arms and angularly disposed to one another, an operating member extending REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,129,712' Southworth Sept. 13, 1938 2,396,044 Fox Mar. 5, 1946 2,411,338 Roberts Nov. 19,1946 2,454,530

' Tiley Nov. 23, 1943 

